Sodium iodide effects on the helical stability of a mainly alanine

Sodium iodide effects on the helical stability of a mainly alanine peptide
Downey, Theresa; Asciutto, Eliana; Madura, Jeffry
Department of Computational Biology
University of Pittsburgh
Department of Chemistry and Biochemistry Center for Computational Sciences
Duquesne University
Peptide-based drugs have the potential to treat many diseases. Some α-helical peptides have the ability
to enter cells by crossing the lipid bilayer. However, the environment could affect the peptide’s α-helical
stability and hinder its entrance into the cell. To overcome this difficulty both experimental and
computational teams have developed various techniques to stabilize the α-helix configuration of peptides.
One method is to select ions to stabilize the α-helix secondary structure in an aqueous environment. This
work studied the stabilization effects of the iodide anion on a mainly alanine peptide as a portion of the
entire Hofmeister series investigation. Additionally, Replica Exchange Molecular Dynamics was employed
to increase the sampling of configurations of the system throughout simulation. According to previous
studies, the iodide ion is expected to stabilize the peptide less than perchlorate in an aqueous
environment according to the Hofmeister series.